Gearboxes of commercial vehicles are divided into a main gearbox, a split group gearbox (GV) and a relay group gearbox (GP). Modern gearboxes, especially in commercial vehicles, have a pneumatically supported control unit, which performs pneumatic shifts in the split group gearbox and in the relay group gearbox, while the shifts in the main part of the gearbox are performed manually by the driver, whereupon the exerted force can be supported by the pneumatic system.
A plurality of prior art devices for the hydraulic and/or pneumatic control of a gearbox and/or shifting element are known.
A device for controlling the adjusting device of a gearbox is known, for example, from EP 1 067 319 B1, which comprises a first pressure medium chamber and a second pressure medium chamber, which are separated from one another by a piston that is movable along its longitudinal axis, to which a first and second controllable valve device are provided that are configured as a 3/2-way valve.
These valve devices optionally connect the pressure medium chambers to a pressure medium source or to a pressure medium sink.
Furthermore, a third controllable valve device is provided, which is connected to the first and second controllable valve device as well as to the pressure medium source so that the pressure medium inlet of the first controllable valve device and the pressure medium inlet of the second controllable valve device can optionally be connected to the pressure medium source or separated from it. In this case, the third controllable valve device is a 2/2-way valve.